Tar/Zip/Rar trouble

[J.L. Coenders]

Hi all,
Does anyone know what how to hidden and backup files into an archive with 
tar/zip/rar?
I want to backup my ~/Mail directory, but somehow it doesn't work with 
Fileroller so I want to try it manually (errors). However, I cannot find how 
to pack hidden files. Maybe I am looking for the wrong thing or does anyone 
have another solution to my problem.
And how can I test an archive to see if it works proper?

Thanks,
Jeroen